Schwieter Kenneth E, Johnston Jeffrey N
ACS Catal. 2015;5(11):6559-6562. doi: 10.1021/acscatal.5b01901.
This report details the enantioselective synthesis of β-amino-α-bromo nitroalkanes with β-alkyl substituents, using homogeneous catalysis to prepare either antipode. Use of a bifunctional Brønsted base/acid catalyst allows equal access to either enantiomer of the products, enabling the use of Umpolung Amide Synthesis (UmAS) to prepare the corresponding L- or D-α-amino amide bearing alkyl side chains - overall, in only 4 steps from aldehyde. The approach also addresses an underlying incompatibility between bromonitromethane and solid hydroxide bases.
本报告详细介绍了具有β-烷基取代基的β-氨基-α-溴代硝基烷烃的对映选择性合成，采用均相催化制备任意一种对映体。使用双功能布朗斯特碱/酸催化剂可平等地获得产物的任意一种对映体，从而能够利用极性翻转酰胺合成法（UmAS）制备带有烷基侧链的相应L-或D-α-氨基酰胺——总体而言，从醛出发仅需4步。该方法还解决了溴硝基甲烷与固体氢氧化物碱之间潜在的不相容性问题。
